Induction electricity meter



Feb; 16 1926. 1,573,546

. VJ. HARRIS INDUCTION ELECTRICITY METER Filed June 15. 1925 Fig.1.

Fig. 2.

INVENTOR Jesse Harms ATTORNEY Patented Feb. 16, 1926.

UNITED era JESSE HARRIS, or LA-FAYETTE, rnniann, essienon To asse s ELECTRIC MANU FACTURING COMPANY, OF LAFAYETTE, INDIANA, A .CORPORATION or ILLINOIS.

INDUCTION ELECTRICITY METER.

Application filed June 15, 1925, SerialNo. 37,173.

lily invention relates to induction else-- tricity meters and is of particular service in connection with watthourmeters;

My inventionhas 'tor itsob'ect the'preven tion oferrors in such a meter due to tem perature changes. I accomplish the object of my invention by the provision of a sup" Jlemental magnetic flux jroducin device i i Q 7 having an energizing circuit whose resistance varies upon change in temperature more than the, resistance of the windings of the torque producing magnet system, par

, mental flux producing device being arranged ticularly. the'pressure winding," saidsuppleto have its flu): follow a path that is also followed by iiux set up by saidgmagn'et system.

In the preferred embodiment ofthe in vention the supplemental magneticifiux producing device is arranged in apath for flux 7 produced by said magnet system that shunts the meter armature, this supplemental mag netic iluX producing device having an'ener gizing circuit whose resistance increases and decreases more'up'on" increase'and decrease in temperature than the resistance of said pressure winding increases and decreases, the flux produced by said sup'plemental de vice being arranged to flow oppositely to the flux 01: said magnet system fiowingin said path that shunts-the meter armature. By this mechanism errors due to temperature eifected changes in resistance in the aressure winding '01 the torqu'eproduci-ng magnet system and'alsoerrors due to temperature eifected'changes in the draggingaction of the permanent magnets may be *both overcome. v v v,

The invention will he more fully explained in'con'neetion witlrth'e accompanying drawing in which Fig.1 is a diagrammatic view of one well known formof meter as it is preferably equipped in accordance with my invention, an alternatingcurrent system to which the meter is supplied being lso dias Harms a citithe pressure winding 14.

rammaticall 1 shown and Fi 2 illustrates b 7 b a modification. 4

I have illustrated transmission mains 1; 2'

supplied trom-asuitable source of current which, iiran alternating current system of distribution, may be the secondary-3, whose primary dis-shown as-being supplied from an alternating current generating dynamo 5, The load'illustrated is in the form ofincandescent electric lamps v 6. The energy consumed by the'load is measured by a watt deter, usually-of the induction watthour or integrating'typ'e, suclira'meter being illus-Q trated in the drawing. 1 This meter is;in-.- elusive of a11.,upright spindle or shaft 7 suitably held .in'b'earings 8 and 9. A hori zontal aluminum armature disc 10 is carried by the spindle on which the disc 'is ri'gidly secured. This disc is turn-edproportionate ly to the energy consumed by the load'bymagnet-system that-is inclusive of acurrent cluded in' the main-'2. The pressure magnet 1s inclus ve of a" U-shaped laminated iron cert-3'13 whose legs are surrounded by} the 15 wh-ich-s embraces the peripheral portion of the disc ivltll'whlcll 1t 15 111 inductive rela-' was l l wljiich are connected in series "in the tion. llhe meter parts illustrated and described constitute a meter motor whose armature 1G and spindle 7 turn proportionate- 15* to the wattage in a' manner well known to those familiar with the art. i

A worm 18 is pro'vi'led upon the spindle 7 and is in mesh with a pinion 19 that is in driving relation with the wountin'gftrain of the meter, as is well understood without the necessity of further illustration;

Qiiadrature relation o't'the magnetic fields due to the current and pressure windings is eifected'b'y ineansof the closed conductors 20, 20 which surround the endsoi the pressurecore 1'3 and are adjustable for calibra tion along these core ends to regulate the secondary relation of these conductors with The conductors 20, 20 maybe in the'nature of non-magnetic metallic plates with holes therethrough through which the ends of the core 13 are passed. A non-magnetic metallic plate 21 has two holes formed therethrough through which the ends of core 13 are also passed, to provide closed conductors that compensate for friction. This plate adjustable for calibration crosswise of the lin'ibs of the core 13.

The temperature eliected changes in the torque of the meter are in a direction to assist in the correction or he errors at the damping magnet, but do not proceed far enough.

I provide a lan'iinated iron core 22 between the arms of the J shaped pressure core 13, thereby establishing a magnetic shunt for the greater part of the flux of the pressure coils ll, and upon this shunt core is placed a coil in the arrangement shown in Fig. l or in the arrangcmnt shown in Fig. In l the coil 23 is shown in bridge ot the mains l and 2. in Fig. 2 the coil 2t is in secondary relation to the pressure winding ll. These coils are of insulated wire having a high temperature coeilicientof resistance such as iron, the coils being so directed as to furnish flux that opposes the passage of the pressure winding flux between the arms of the core 13.

The meter is calibrated as usual at some selected. mean temperature to correctly register various loads. ll hen a meter so calibrated is subject to a higher temperature, the damping magnet will become less effective due to the reduction of its magnetic permeability as will also the torque produced by the torque producing magnet system of the meter and to an extent to cause the meter to run faster than it should for correct registration. Conversely it the temperature is reduced below that at whicn th meter was initially calibrated the meter will run slower than it should. The correcting flux due to the winding 28 or the winding 2%, opposing, as it does, the'passage of the flux produced by the magnet 5* torn between the arms of the core 13' will so modif the tor-one )rosaid closed conductor, and a supplemental magnetic flux producing device having a magnetizable core arranged in a path for flux produced by said magnet system thatshunts the meter armature and having an energizing circuit whose resistance increases and decreases more upon increase and decrease in temperature than the resistance of said pressure winding increases and decreases, said supplemental flux producing device being arranged to have its flux flow oppositely to the this: of said magnet system flowing in said path that shunts the armature to reduce the torque efiecting flux upon increase in temperature and to increase the torque effecting flux upon reduction in tem perature to compensate for teineparture et tested changes in the dragging action 01"- the damping magnet.

An induction electricity meter includ ing a tcrqueproducing magnet system provided with current and pressure windings in inductive relation to the motor armature, and a supplemental magnetic fin producing device having a magnetizable core arranged in a path for flux produced by said magnet system. that shunts the meter armature and having an energizing circuit whose resistance increases and decreases more upon increase and decrease in temperature than the resistance of said pressure winding in creases and decreases, said supplemental tlui: producing device being arranged to have its flux flow oppositely to the flux of said magnet system flowing in said path that shunts the arn'iature to reduce the torque effecting flux upon increase in temperature and to increase the torque effecting flux upon reduction in temperature.

3. An induction electricity meter including a torque producing magnet system provided with current and pressure windings in inductive relation to the motor armature, and a supplemental magnetic flux producing de ice having a magnetizahle core arranged in a path for flux produced by said magnet system that shunts the meter armature and having an energizing circuit whose resistance increases and decreases more upon increase and decrease in temperature than the resistance of said'pressure winding increases and decreases, said supplemental flux producing device being arranged to have its flux flow oppositely to the flux of said magnet system flowing in said path that shunts the armature.

In witness whereof, I hereunto subscribe my name.

esse ana, 

